104 



THE SCOLYTID BEETLES. 



the inner bark. The broods occupy the bark of stumps and logs 

 and the trunks of standing trees from the ground to the branches, 

 or on into the tops. Fresh attacks on living trees cause a flow of 

 resin or red boring dust in the loose bark and around the base of the 

 trees. This species is capable of extensive depredations on the 

 largest and best larch, but apparently prefers to infest injured, dying, 

 and felled trees. 



Fig. 63.— The eastern larch beetle: Egg galleries and larval mines. (Author's illustration.) 



SEASONAL HISTORY. 



While comparatively few details on the seasonal history of this 

 species have been determined, it is evident that it passes the winter, 

 principally in the adult stage, beneath the bark of trees, stumps, etc., 

 attacked during the preceding summer, and activity begins with the 

 first warm weather in April, May, or June. It also appears that 

 there is but one generation annually, and, owing to the almost com- 

 plete development of the broods in the fall, there is probably not 



